An old man dies. It is only when his housekeeper returns some unused tablets to the chemist that any sort of suspicion clouds the issue. Hardy is brought in to conduct various tests and he questions the principals in the case. The conclusion he reaches is arrived at only after he has very carefully weighed up all the factors in the case, and even so his decision is a surprise. Guest stars Lewis Fiander, Brian Oulton and Reginald Barratt.